Photographic film containing hardened gelatin



April 22, 1952 M. T. ORINIK 2,593,912

PHOTOGRAPHIC FILM CONTAINING HARDENED GELATIN Filed Nov. 19, 1948 ELAT/NO SILVER HAL/DE EMULSION 3 LAYER co/vm/w/va AN ORGAN/C 2 HARDEN/NG AGENT I GELA TIN SUBB/NG LAYER co/vm uw/va FORMAL DEHVDE OR GLVOXAL SUPPORT F IG. 1

GELAT/NO SILVER HAL/DE EMULSION LAYER 4 GELAT/N SUBB/NG LAYER CONTAINING 2 FORMALDEHVDE OR GLYOXAL j/j fisz/PPo/i'r 6ELAT/N SUBB/NG LAYER co/vmuvm/a 5 1 \q FORMALDEHVDE OR GLVOXAL NON-CURL/NG OR ANTl-HALAT/ON LAYER CONTAIN/N6 AN ORGAN/C HARDEN/NG AGENT FIG. 2

INVENTOR MICHAEL 7T OR/N/K ATTORN EYS Patented Apr. 22, 1952 UNITED STATES PATENT OFFICE PHOTOGRAPHIC FILM CONTAINING HARDENED GELATIN Michael T. Orinik, Binghamton, N; Y., assignor to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware Application November 19, 1948,'Serial No 61,137

Claims. (Cl. 95-9) 1 2 This invention relates to photographic film tions or dispersions. For these reasons, theart and particularly to-an improved photographic has always been of the belief that all organic film containing hardened gelatin. hardening agents are inoperative in the usual It isknown that photographic film is prepared gelatin subbing compositions. This belief was by the coating of a gelatino silver halide emul- .5 based on the assumption that the hardening acsion layeron a transparent film base. Cellulose tion of the organic hardening agents is strongly nitrate has been used primarily because of its inhibited by the presence of either acid or orhighly d s l physi a p p r s, su as ganio solvent in the subbing solution or disperstrength, rigidity, and toughness. It possesses, sion. ow 0 t di dis dv tage in that it Inorganic salts of trivalent chromium, such as extremely inflammable- With the advent O chromium chloride, chromium nitrate, chrome amateur processing and projection of 8 mmsand m and t like, h ve also been suggested as 161mm. film, it has been desirable to provide a hardening agents i -gelatin subbing composi...

non-inflammable film, and the photographic inmons- Their presence i elatin subbing soludustly achieve this end has been using 691111" tions or compositions also causes electrolytic prelose ester film basescellulose cipitation of the gelatin over a period of time so i of m F contammg 56-58% of that theresulting subbing solution loses strength bmed aceticacid content, has been found mon Standing and subtracts from the adhesive ferior photographically to cellulose nitrate. properties between the film base and t adjagelatino silver halide emulsion layer and as- .sociated'non-curl, filter, and anti-halation lay- .erstoinsure adhesion between the coated layers and the filmbase proper. Slight variations in .to reticulation, peeling, and frilling of the coated Cellulose esters of higher acid content have been cent gelatin emulsion or nomcurl 1ayers foupd to be extremely dlfficult 9 process "afesplte though it is possible to secure suificient adhesion their mor ed es1mb1e photographlc pltopertles' of the coated photo-sensitive layers for short The pimcltoal drawback of the hlghfer cenu' periods of time, ithas been found that storage for lose acetic acid esters (58-61% of combined aceeriods of time greater than Six months is deb tic acid) has been the difficulty in applying the gterious to the product as a Whole The present invention has as an object to overcome the above-mentioned difficulties and to provide an improved photographic film containing'hardened gelatin.

Another object is to provide a non-desensitizlayers from the film base. ing, non-corrosive subbing solution of hardened 11-, is t practjcejn the photographic art to gelatin for subbing cellulose derivative film suptemperature, humidity, hardness, eto., give rise apply a special layer, known as the subbing layporbser, to promote adhesion of the gelatino silver hal- 5 A further oblect 15 to prom a ge1atm Ksubbmg id l i layer th auXi1ia,ry 1ayers composition free from electrolytic precipitation. t m uggested-for the subbing of a photo Otherobjects and advantages will appear from graphic film baseinclude cellulose nitrate-plasthe following descrip i ticizer mixtures, gelatin-cellulose nitrate mix- I have found t Of all t O c hardentures, modifiedsgelatin layers-over-coated with ing agents employed for hardening latin-Subs plaingelatin, etc. and gelatino silver halide emulsion layers, From a subbingstandpoint, many attempts formaldehyde and glyoxal in specific amounts havebeen madetto hardenthe gelatin in asubfunction most satisfactorily as hardening agents bing solution chemically to reduce its moisture for gelatin subbing solutions. These hardening susceptibility-and improve'other physical charagents when employed in specific amounts or acteristics. Thecommonly employed hardening concentrations possess none of the disadvantages agents, such' as formaldehyde, glyoxal= and the referred to above. The formaldehyde or gyloxal like, give sometimes the impression of-showin g hardening agents are incorporated into the gelapoor solubility in the usual subbing composition tin subbing composition containing gelatin, bycausing an electrolytic"precipitation*of the water, dispersing medium such as an organic gelatin fromthe subbing-solution. Another diffiacid, acetic acid and the like, cellulose derivative, culty encountered is that the 1 gelatin subbing as Will be pointed out hereinafter, and an organic compositions are stronglyacid tin nature-and solvent or a mixture of such solvents.

many of the organic:hardeningagents' employed The gelatin subbing compositions are preoperatebest-in neutral or alkaline subbing solupared by adding the formaldehyde or glyoxal to a gelatin dispersion containing gelatin, water and a dispersing medium and thereafter adding the dispersion to an organic solvent, such as, for example, methanol, ethanol, acetone, methyl acetate, methyl cellosolve, or a mixture of such solvents, or by adding the formaldehyde or glyoxal to the finished gelatin subbing composition, i. e., containing the organic solvents or mixtures thereof. The solution thus obtained is deposited on one or both sides of a cellulose derivative film base in any convenient manner, the subbing operation preferably being carried out in connection with or as a part of the process of making the film support itself. The gelatin subbing solutions made up as above described are clear dispersions from which the gelatin is not precipitated by either the formaldehyde or glyoXal.

The amount or concentration of formaldehyde or glyoxal to be added to the gelatin subbing solution depends on the amount of the organic hardening agent used in any one ofthe adjacent gelatin layers such as in the gelatino silver halide emulsion layer, the non-curling or anti-halation layer. .The organic hardening agent employed in any one of the adjacent layers may be any one of the reactive aldehyde or keto compounds commonly employed for this purpose, such as, for example, formaldehyde, glyoxal, acetaldehyde, hydroxyaldehydes, such as glycolaldehyde, ketoaldehydes, such as methylglyoxal, diacetyl, and the like. Of these, glyoxal and formaldehyde are preferred. Optimum adhesion is obtained when the amount of formaldehyde or glyoxal in the gelatin subbing solution is equal to or is in limited excess of that employed in any one of the adjacent layers. By careful control of the amount of formaldehyde or glyoxal in the gelatin subbing layer, I have found that there exists a critical relationship between the amount of organic hardenerinthe gelatino silver halide emulsion layer and the amount of glyoxal or formaldehyde in the gelatin subbing layer. When the amount of hardener in the gelatin subbing layer deviates from the critical optimum range, deleterious effects, such as poor adhesion, frilling, and artificial aging with consequent photographic deterioration of the emulsion results. The critical relationship which I have discovered is that the proportion of formaldehyde or glyoxal, in relation to the amount of dry gelatin, in the gelatin subbing solution or composition must be at least equal to and should not exceed by more than parts per thousand the proportion of organic hardening agent, in relation to the amount of dry gelatin, in the adjacent gelatin layer. For example, if the amount of the organic hardening agent in the adjacent gelatin layer is 0.4% (based on the Weight of dry gelatin), the amount of formaldehyde or glyoxal in the gelatin subbing layer should be from 0.4 to 0.9% (based on the Weight of dry gelatin in the subbing composition). This relationship with respect to amounts or concentrations is so critical that any deviation will subtract from the adhesive properties of the subbing composition and will give rise to the condition known as frilling.

The amount of organic hardening agent which may be added to gelatinous silver halide layers normally varies from 0.5 grain to 100 grams per kilogram of dry gelatin, and depends on the type of hardener and the strength of the gelatin solution used,

When formaldehyde or glyoxal are employed as hardening agents for gelatinous silver halide emulsions or non-curling layers, amounts ranging from 0.5 gram to 7.5 grams of hardener per kilogram of dry gelatin are commonly preferred. For all practical purposes, I have found that when the ratio of formaldehyde or glyoxal to gelatin in the subbing layer is just equal to the ratio of organic hardener to gelatin in the adjacent emulsion or non-curling layer, all the layers possess mechanical characteristics which promote normal flexing without cracking, or distorting any one of the layers. A slight excess of formaldehyde or glyoxal in the gelatin subbing layer within the foregoing limits seems to cause a more positive bonding action at the interface.

The cellulose derivative used in the gelatin subbing composition in accordance with this invention and to which said compositions are applied are cellulose nitrate,-cellulose acetate, cellulose triacetate, cellulose formate, cellulose propionate, cellulose butyrate, cellulose acetate-butyrate, cellulose acetate-propionate, and the like, the partially hydrolyzed derivatives thereof such as hydrolyzed cellulose acetate, hydrolyzed cellulose acetate-propionate, and the like, and ethers of cellulose such as ethyl ether, benzyl ether and the like.

It will be appreciated that each different type of cellulose ester, hydrolyzed derivative ester and mixtures thereof requires slightly different solvent or solvent combination. The solvent or solvent mixture employed is such that it will have a solvent or at least a softening or swelling action on the film base so as to stick or anchor the gelatin upon the area of the cellulose derivative film support which has been softened or swollen. For example, with a cellulose acetate base, a low molecular Weight alcohol, e. g., methanol, ethanol or the like, or a ketone such as acetone or a mixture of 3 parts of acetone to 1 part of alcohol may be employed. With cellulose acetate-propionate film base, an alkyl ester such as, for example, methyl acetate, ethyl acetate, butyl acetate, and the like, either alone or with methanol 0r lA-dioxane may be effectively employed. Such solvents or mixtures thereof employed for the ether cellulose derivative film supports are well known to those skilled in the art and a further disclosure of them need not be made herein. It may be mentioned at this point that the nature of the gelatin dispersing medium solvent or solvent mixture is immaterial to the practice of the present invention so long as the dilute dispersing medium, whether it be an organic acid, heterocyclic nitrogenous base, lactone, or the like, disperses the gelatin in water, and the solvent or solvent mixture wets or bites into the cellulose derivative. Since materials suitable for the film base and their solvent proportions are well known no diiiiculty is presented in selecting a suitable solvent or solvent mixture for use in the gelatin subbing compositions.

The gelatin subbing compositions of the present invention are not only useful for the subbing of the foregoing cellulose derivative film supports, but are also useful in subbing cellulose derivative film supports containing suspended pigments of an organic or inorganic nature or both. The gelatin subbing compositions are also useful in subbing cellulose film supports for the application of non-curling and anti-halation layers.

In the accompanying drawing, the two figures are enlarged section views of a photographic film having gelatin subbing layers prepared in accordance with the present invention. 7

Figure 1 represents an embodiment of the invention in which the gelatin subbing layer is interposed between the silver halide emulsion and support.

Figure 2 represents an embodiment of the in: vention in which the gelatin subbing layer is deposited on both sides-of the support.

In Figures 1 and 2, l is the support, 2 the gelatin subbing layer containing either formaldehyde or glyoxal as the hardening agent, 3 the gelatino silver halide emulsion layer containing an organic hardening agent, 4 a gelatino silver halide emulsion layer, and 5 the non-curling or anti-halation layer containing either formaldehyde or glyoxal.

The following specific examples illustrate several of the various methods of applying the gelatin subbing compositions and it will be understood that these examples merely represent the preferred embodiments and are not to be considered as limitative. All parts and percentages are by weight.

Example I A film base of cellulose acetate having a combined acetic acid content of 59% was coated with the following gelatinous substrative composition:

Parts Gelatin 8 Water 20 Acetic acid 1.2

Glyoxal 0.02 Cellulose acetate (56% combined acetic acid) 6 The foregoing dispersion was added to a mixture consisting of 400 parts of methyl alcohol and 600 parts of acetone to make a clear subbing solution.

After the subbing layer had dried, an acid type, gelatino silver halide emulsion layer, in which the concentration of formaldehyde hardener is 2.5 parts per 1000 parts of gelatin on the dry basis, was coated directly thereon. After exposure, developing, and processing, the emulsion adhered tenaciously to the cellulose acetate film support and the processed film showed no frilling.

Example II A film base of cellulose acetate-propionate having an acetyl content of 30% and a propionyl content of 13.5%, was coated on both sides with the following subbing composition:

Parts Gelatin 8 Water 25 Acetic acid 1.2 Formaldehyde 0.06 Cellulose acetate-propionate 6 The foregoing dispersion was added to the same solvent mixture as in Example I to make a clear gelatin subbing solution.

After the subbing layers had dried, a non-curling gelatin layer was coated on one side and a gelatino silver halide emulsion layer coated on the other side of the subbed film. The concentration of glyoxal hardening agent in both coated layers is 5 parts per 1000 parts of gelatin on the dry basis. After storage for several minutes, both the non-curl layer and the gelatino silver halide emulsion layer showed strong adhesion to the cellulose acetate-propionate film base.

Example III For coating a cellulose acetate-butyrate film base, having a combined acid ratio of 30% acetic acid and 17% butyric acid with a gelatin, mncurling layer inwhich the concentration of formaldehyde hardener is 4 parts per 1000 parts of gelatin on the dry basis, the following subbing solution was employed:

Parts Gelatin 10 Water 20 Acetic acid 1 Glyoxal 0.04 Cellulose acetate-butyrate 7 The foregoing dispersion was added to a mixture consisting of equal parts of methanol and acetone to make a clear subbing solution.

The subbed photographic film bases produced according to the present invention, in addition to prompting better adhesion without frilling and peeling were found to be very satisfactory from the standpoint of physical requirements such as high strength, flexibility, and good water resistance.

I claim:

1. A photographic film comprising a cellulose derivative support selected from the class consisting of cellulose ethers and esters, a gelatino silver halide emulsion layer containing an organic hardening agent in an amount ranging from 0.5 gram to 7.5 grams per kilogram of dry gelatin and a gelatin subbing layer between said support and said emulsion layer, said subbing layer containing in addition to gelatin a dispersion of a cellulose derivative and a hardening agent of the class consisting of formaldehyde and glyoxal, the proportion of the latter hardening agent in relation to the Weight of dry gelatin in said subbing layer being in an amount ranging from 0.5 gram to 12.5 grams per kilogram of dry gelatin and at least equal to and not exceeding by more than 5 grams per kilogram of dry gelatin the proportion of the organic hardening agent, in relation to the weight of dry gelatin, in said emulsion layer.

2. A photographic film according to claim 1 wherein the gelatin subbin layer contains glyoxal.

3. A photographic film according to claim 1 wherein the silver halide emulsion layer contains 5 grams of glyoxal per kilogram of dry gelatin.

4. A photographic film comprising a cellulose derivative support selected from the class consisting of cellulose ethers and esters, carrying on one side of said support a gelatino silver halide emulsion layer, and on the opposite side of said support a non-curling gelatin layer containing an organic hardening agent in an amount ranging from 0.5 gram to 7.5 grams per kilogram of dry gelatin, a gelatin subbing layer between said non-curling layer and said support, said subbing layer containing in addition to gelatin, a dispersion of a cellulose derivative selected from the class consisting of cellulose ethers and esters, and an organic hardening agent selected from the class consisting of formaldehyde and glyoxal in an amount ranging from 0.5 gram to 12.5 grams per kilogram of dry gelatin, the proportion of the latter hardening agent, in relation to the weight of dry gelatin in said subbing layer, being at least equal to and not exceeding by more than 5 grams per kilogram of dry gelatin the proportion of the organic hardening agent in relation to the weight of dry gelatin in said non-curling layer.

7 I 5. A photographic film according to claim 4 Number wherein the non-curling layer contains 5 grams 1,870,354 of glyoxal per kilogram of dry gelatin. 2,054,284 MICHAEL T. ORINIK. 2,146,907 5 2,271,228 REFERENCES CITED 2,341,877

The following references are of record in the file of this patent:

UNITED STATES PATENTS m g g Number Name Date 723,054 Smalley Mar. 17, 1903 Name Date Brunken Aug. 9, 1932 Forstmann Sept. 15, 1936 Nadeau Feb. 14, 1939 Nadeau Jan. 2'7, 1942 Middleton et a1. Feb. 15, 1944 FOREIGN PATENTS Country Date Great Britain of 1894 

1. A PHOTOGRAPHIC FILM COMPRISING A CELLULOSE DERIVATIVE SUPPORT SELECTED FROM THE CLASS CONSISTING OF CELLULOSE ETHERS AND ESTERS, A GELATINO SILVER HALIDE EMULSION LAYER CONTAINING AN ORGANIC HARDENING AGENT IN AN AMOUNT RANGING FROM 0.5 GRAM TO 7.5 GRAMS PER KILOGRAM OF DRY GELATIN AND A GELATIN SUBBING LAYER BETWEEN SAID SUPPORT AND SAID EMULSION LAYER, SAID SUBBING LAYER CONTAINING IN ADDITION TO GELATIN A DISPERSION OF A CELLULOSE DERIVATIVE AND A HARDENING AGENT OF THE CLASS CONSISTING OF FORMALDEHYDE AND GLYOXAL, THE PROPORTION OF THE LATTER HARDENING AGENT IN RELATION TO THE WEIGHT OF DRY GELATIN IN SAID SUBBING LAYER BEING IN AN AMOUNT RANGING FROM 0.5 GRAM TO 12.5 GRAMS PER KILOGRAM OF DRY GELATIN AND AT LEAST EQUAL TO AND NOT EXCEEDING BY MORE THAN 5 GRAMS PER KILOGRAM OF DRY GELATIN THE PROPORTION OF THE ORGANIC HARDENING AGENT, IN RELATION TO THE WEIGHT OF DRY GELATIN, IN SAID EMULSION LAYER. 